Measuring the Electronic Bandgap of Carbon Nanotube Networks in Non-Ideal Diodes.

The measurement of the electronic bandgap and exciton binding energy in quasi-one-dimensional materials such as carbon nanotubes is challenging due to many-body effects and strong electron-electron interactions. Unlike bulk semiconductors, where the electronic bandgap is well known, the optical resonance in low-dimensional semiconductors is dominated by excitons, making their electronic bandgap more difficult to measure. In this work, we measure the electronic bandgap of networks of polymer-wrapped semiconducting single-walled carbon nanotubes (s-SWCNTs) using non-ideal diodes.

Inactivation of VRK1 sensitizes ovarian cancer to PARP inhibition through regulating DNA-PK stability.

Ovarian cancer is the leading cause of gynecologic cancer death. Among the most innovative anti-cancer approaches, the genetic concept of synthetic lethality is that mutations in multiple genes work synergistically to effect cell death. Previous studies found that although vaccinia-related kinase-1 (VRK1) associates with DNA damage repair proteins, its underlying mechanisms remain unclear.

Degradation of AZGP1 suppresses apoptosis and facilitates cholangiocarcinoma tumorigenesis via TRIM25.

Alpha-2-Glycoprotein 1, Zinc-binding (AZGP1, ZAG) is a secreted protein that is synthesized by adipocytes and epithelial cells; it is downregulated in several malignancies such as breast, prostate, liver and lung cancers. However, its function remains unclear in cholangiocarcinoma (CCA). Here, we evaluated the impact AZGP1 in CCA using Gene Expression Omnibus (GEO) and GEPIA.

TCOF1 promotes the colorectal cancer progression by stabilizing β-catenin.

Colorectal cancer (CRC) is one of the highest mortality rates worldwide, and various studies reported to the occurrence of CRC. In particular, the Wnt/β-catenin pathway is known to be a major factor in the progression of CRC and β-catenin involved in the expression of its downstream target genes. We searched for TCOF1 through sliver staining to identify a new binding partner for β-catenin and to investigate the role of the gene involved in CRC.

Andreev Reflection and Klein Tunneling in High-Temperature Superconductor-Graphene Junctions.

Scattering processes in quantum materials emerge as resonances in electronic transport, including confined modes, Andreev states, and Yu-Shiba-Rusinov states. However, in most instances, these resonances are driven by a single scattering mechanism. Here, we show the appearance of resonances due to the combination of two simultaneous scattering mechanisms, one from superconductivity and the other from graphene p-n junctions.

All-Carbon Nanotube Solar Cell Devices Mimic Photosynthesis.

Both solar cells and photosynthetic systems employ a two-step process of light absorption and energy conversion. In photosynthesis, they are performed by distinct proteins. However, conventional solar cells use the same semiconductor for optical absorption and electron-hole separation, leading to inefficiencies.

Direct Measurement of the Electron Beam Spatial Intensity Profile via Carbon Nanotube Tomography.

Electron microscopes are ubiquitous across the scientific landscape and have been improved to achieve ever smaller beam spots, a key parameter that determines the instrument's resolution. However, the traditional techniques to characterize the electron beam have limited effectiveness for today's instruments. Consequently, there is an ongoing need to develop detection technologies that can potentially measure the smallest electron beam, which is valuable for the continual advancement of microscope performance.

Tunneling Spectroscopy of Quantum Hall States in Bilayer Graphene p-n Junctions.

We report tunneling transport in spatially controlled networks of quantum Hall (QH) edge states in bilayer graphene. By manipulating the separation, location, and spatial span of QH edge states via gate-defined electrostatics, we observe resonant tunneling between copropagating QH states across incompressible strips. Employing spectroscopic tunneling measurements and an analytical model, we characterize the energy gap, width, density of states, and compressibility of the QH edge states with high precision and sensitivity within the same device.

Gate-Tunable Graphene-WSe Heterojunctions at the Schottky-Mott Limit.

Metal-semiconductor interfaces, known as Schottky junctions, have long been hindered by defects and impurities. Such imperfections dominate the electrical characteristics of the junction by pinning the metal Fermi energy. Here, a graphene-WSe p-type Schottky junction, which exhibits a lack of Fermi level pinning, is studied.

Atomic-Scale Characterization of Graphene p-n Junctions for Electron-Optical Applications.

Graphene p-n junctions offer a potentially powerful approach toward controlling electron trajectories via collimation and focusing in ballistic solid-state devices. The ability of p-n junctions to control electron trajectories depends crucially on the doping profile and roughness of the junction. Here, we use four-probe scanning tunneling microscopy and spectroscopy (STM/STS) to characterize two state-of-the-art graphene p-n junction geometries at the atomic scale, one with CMOS polySi gates and another with naturally cleaved graphite gates.

Two-Parameter Quasi-Ballistic Transport Model for Nanoscale Transistors.

We show that by adding only two fitting parameters to a purely ballistic transport model, we can accurately characterize the current-voltage characteristics of nanoscale MOSFETs. The model is an extension of Natori's model and includes transmission probability and drain-channel coupling parameter. The latter parameter gives rise to a theoretical R that is significantly larger than those predicted previously.

Longitudinal Effects of Body Mass Index and Self-Esteem on Adjustment From Early to Late Adolescence: A Latent Growth Model.

Background: Mental and physical development during adolescence is a factor that may affect quality of life in adulthood.

Purpose: The aims of this study were to investigate the developmental trajectories of body mass index (BMI), self-esteem, and adjustment among students from early to late adolescence and to examine the longitudinal relationships among these variables.

Methods: Data from 2006 to 2012 were collected from the Korean Welfare Panel Study.

Quantum transport in graphene junctions with moiré superlattice modulation.

We present simulations of quantum transport in graphene junctions (Js) in which moiré superlattice potentials are incorporated to demonstrate the interplay between Js and moiré superlattice potentials. It is shown that the longitudinal and Hall resistivity maps can be strongly modulated by the J profile, junction height, and moiré potentials. Device resistance measurements are subsequently performed on graphene/hexagonal- boron-nitride heterostructure samples with accurate alignment of crystallographic orientations to complement and support the simulation results.

Change in Renal Function among HIV-Infected Koreans Receiving Tenofovir Disoproxil Fumarate-Backbone Antiretroviral Therapy: A 3-Year Follow-Up Study.

Purpose: Tenofovir disoproxil fumarate (TDF) is commonly prescribed as a fixed-dose, co-formulated antiretroviral drug for HIV-1 infection. The major concern of long-term TDF use is renal dysfunction. However, little is known about the long-term patterns of changes in renal function in HIV-infected Koreans receiving TDF.

Three fundamental devices in one: a reconfigurable multifunctional device in two-dimensional WSe.

The three pillars of semiconductor device technologies are (1) the p-n diode, (2) the metal-oxide-semiconductor field-effect transistor and (3) the bipolar junction transistor. They have enabled the unprecedented growth in the field of information technology that we see today. Until recently, the technological revolution for better, faster and more efficient devices has been governed by scaling down the device dimensions following Moore's Law.

Long Pentraxin 3 as a Predictive Marker of Mortality in Severe Septic Patients Who Received Successful Early Goal-Directed Therapy.

Purpose: Pentraxin 3 (PTX3) has been suggested to be a prognostic marker of mortality in severe sepsis. Currently, there are limited data on biomarkers including PTX3 that can be used to predict mortality in severe sepsis patients who have undergone successful initial resuscitation through early goal-directed therapy (EGDT).

Materials And Methods: A prospective cohort study was conducted among 83 severe sepsis patients with fulfillment of all EGDT components and the achievement of final goal.

Predictive factors for unfavorable outcomes of tuberculous pericarditis in human immunodeficiency virus-uninfected patients in an intermediate tuberculosis burden country.

Background: In areas where Mycobacterium tuberculosis is endemic, tuberculosis is known to be the most common cause of pericarditis. However, the difficulty in diagnosis may lead to late complications such as constrictive pericarditis and increased mortality. Therefore, identification of patients at a high risk for poor prognosis, and prompt initiation of treatment are important in the outcome of TB pericarditis.

Large Bandgap Shrinkage from Doping and Dielectric Interface in Semiconducting Carbon Nanotubes.

The bandgap of a semiconductor is one of its most important electronic properties. It is often considered to be a fixed property of the semiconductor. As the dimensions of semiconductors reduce, however, many-body effects become dominant.

Bipolar Junction Transistors in Two-Dimensional WSe2 with Large Current and Photocurrent Gains.

In the development of semiconductor devices, the bipolar junction transistor (BJT) features prominently as being the first solid state transistor that helped to usher in the digital revolution. For any new semiconductor, therefore, the fabrication and characterization of the BJT are important for both technological importance and historical significance. Here, we demonstrate a BJT device in exfoliated TMD semiconductor WSe2.

The Effects of Tonsillectomy Education Using Smartphone Text Message for Mothers and Children Undergoing Tonsillectomy: A Randomized Controlled Trial.

Background: Tonsillectomy is the most common type of surgical procedure performed in preschool children. Due to short period of hospitalization, mothers are expected to manage their children's care at home. However, they are rarely provided with sufficient information about postoperative management.

Delaying diagnostic procedure significantly increases mortality in patients with invasive mucormycosis.

Invasive mucormycosis is an uncommon but increasing life-threatening fungal infection. The present study investigated clinical characteristics and mortality among patients diagnosed as invasive mucormycosis infection. We retrospectively reviewed a total of 24 histologically proven cases of invasive mucormycosis at two tertiary care referral hospitals between November 2005 and February 2014.

Ideal graphene/silicon Schottky junction diodes.

The proper understanding of semiconductor devices begins at the metal-semiconductor interface. The metal/semiconductor interface itself can also be an important device, as Schottky junctions often forms when the doping in the semiconductors is low. Here, we extend the analysis of metal-silicon Schottky junctions by using graphene, an atomically thin semimetal.

Electronic excitations in graphene in the 1-50 eV range: the π and π + σ peaks are not plasmons.

The field of plasmonics relies on light coupling strongly to plasmons as collective excitations. The energy loss function of graphene is dominated by two peaks at ∼5 and ∼15 eV, known as π and π + σ plasmons, respectively. We use electron energy-loss spectroscopy in an aberration-corrected scanning transmission electron microscope and density functional theory to show that between 1 to 50 eV, these prominent π and π + σ peaks are not plasmons, but single-particle interband excitations.

The simple predictors of pseudomembranous colitis in patients with hospital-acquired diarrhea: a prospective observational study.

Background/aims: As the incidence rate of and mortality from pseudomembranous colitis (PMC) are increasing worldwide, it is important to study the simple predictive risk factors for PMC among patients with hospital-acquired diarrhea (HAD). This study focused on identifying the clinical risk factors that can easily predict PMC.

Methods: The presumed HAD patients were prospectively recruited at the Hallym University Kangdong Sacred Heart Hospital.

Quantum efficiency and capture cross section of first and second excitonic transitions of single-walled carbon nanotubes measured through photoconductivity.

Comparing photoconductivity measurements, using p-n diodes formed along individual single-walled carbon nanotubes (SWNT), with modeling results, allows determination of the quantum efficiency, optical capture cross section, and oscillator strength of the first (E11) and second (E22) excitonic transitions of SWNTs. This is in the infrared region of the spectrum, where little experimental work on SWNT optical absorption has been reported to date. We estimate quantum efficiency (η) ~1-5% and provide a correlation of η, capture cross section, and oscillator strength for E11 and E22 with nanotube diameter.